Porous Carbon Electrode With Conductive Polymer Coating

• US 20100008021A1
• Filed: 05/25/2007
• Published: 01/14/2010
• Est. Priority Date: 05/31/2006
• Status: Active Grant

• Current Assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften e.V. (Max-Planck-Gesellschaft zur Frderung der Wissenschaften e)
• Original Assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften e.V. (Max-Planck-Gesellschaft zur Frderung der Wissenschaften e)
• Inventors: Smarsly, Bernd, Guo, Yu-Guo, Hu, Yong-Sheng, Fan, Lizhen, Adelhelm, Philipp, Antonietti, Markus, Maier, Joachim
• Granted Patent: US 8,164,881 B2
• Time in Patent Office: Days
• US Class Current: 361/502
• CPC Class Codes: C01B 32/05 Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
• CPC Class Codes: H01G 11/24 characterised by structural features of the materials making up or comprised in the electrodes, e.g. form, surface area or porosity; characterised by the structural features of powders or particles used therefor
• CPC Class Codes: H01G 11/26 characterised by their structure, e.g. multi-layered, porosity or surface features
• CPC Class Codes: H01G 11/32 Carbon-based
• CPC Class Codes: H01G 11/34 characterised by carbonisation or activation of carbon
• CPC Class Codes: H01G 11/48 Conductive polymers
• CPC Class Codes: H01G 11/86 specially adapted for electrodes carbonisation or activation of carbon for the manufacture of electrodes H01G11/34
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• CPC Class Codes: H01M 4/583 Carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y10T 428/24998 Composite has more than two layers
• CPC Class Codes: Y10T 428/249981 Plural void-containing components

Abstract

An extremely high-performance polyaniline electrode was prepared by potentiostatic deposition of aniline on hierarchically porous carbon monolith (HPCM), which was carbonized from mesophase pitch. A capacitance value of 2200 F g⁻¹ of polyaniline was obtained at a power density of 0.47 kW kg⁻¹ and an energy density of 300 Wh kg⁻¹. This active material deposited on HPCM also has an advantageous high stability. These superior advantages can be attributed to the backbone role of HPCM. This method also has the advantages of not introducing any binder, thus contributing to the increase of ionic conductivity and power density. High specific capacitance, high power and energy density, high stability, and low cost of active material make it very promising for supercapacitors.

Claims

1-28. -28. (canceled)

29. An electrode comprising a conductive carbon material of hierarchical porosity coated with an electrically conductive polymer, wherein the porous electrically conductive carbon material includes graphene stacks and has first and second pores in first and second different pore size ranges respectively, wherein said first pores are of irregular shape in three dimensions, are interconnected to form transport passages through said carbon material and have sizes in the size range from 10 μ

m to 100 nm, wherein said second pores are defined between neighbouring graphene stacks, are of irregular shape in three dimensions, are interconnected, communicate directly or indirectly via other second pores with said first pores and have sizes in the size range from less than 100 nm to 3 nm and wherein said graphene stacks defining said second pores form wall material between said first pores.

30. An electrode in accordance with claim 29, in which, in said porous carbon material, a majority of said second pores have sizes before coating with the electrically conductive polymer in the range from 50 nm to 3 nm, and particularly from 3 nm to 8 nm.

31. An electrode in accordance with claim 30, in which, in said porous carbon material, a majority of said first pores have sizes in the range from 5 μ

m to 500 nm, and particularly in the range from 2 μ

m to 500 nm.

32. An electrode in accordance with claim 29, in which, in said porous carbon material the total pore volume comprising micropores with a volume less than 3 nm, the second pores in the size range from less than 100 nm to 3 nm and the first pores in the size range from 10 μ

m to 100 nm lies in the range from 0.1 to 1.0 cc/g.

33. An electrode in accordance with claim 32, in which, in said porous carbon material, said total pore volume lies in the range from 0.40 cc/g to 0.65 cc/g with the volume of second pores lying in the range from 0.35 cc/g to 0.55 cc/g and the volume of the first pores lying in the range from 0.05 cc/g to 0.1 cc/g.

34. An electrode in accordance with claim 32, in which in said porous carbon material, the ratio of the total pore volume of the second pores to the total pore volume of the first pores lies in the range from 2 to 12.

35. An electrode in accordance with claim 29, in which the porous carbon material has a BET surface in the range from 50 m²/g to 800 m²/g, especially from 250 m²/g to 350 m²/g and particularly of around 350 m²/g.

36. An electrode in accordance with claim 29 in which said porous carbon material has an H/C atomic ratio in the range from 0.3 to 0.01 and preferably in the range from 0.2 to 0.075 and especially of about 0.1.

37. An electrode in accordance with claim 29, wherein said conductive polymer is polyaniline.

38. An electrode in accordance with claim 29, wherein said conductive polymer is at least one of the following polymers:

polypyrrole and polythiophene or a mixture of the foregoing, or a mixture of one or both of them with polyaniline.

39. An electrode in accordance with claim 29, in which the carbon material has been obtained by heat treatment at a temperature in the range from 600°

C. to 1000°

C. to effect conversion to non-graphitic carbon with a required degree of order.

40. An electrode in accordance with claim 29 in which the carbon material has first pores in the size range from 10 μ

m to 100 nm and second pores in the size range from less than 100 nm to 3 nm, a specific surface area in the range from 50 m²/g to 800 m²/g, especially around 300 m²/g and a pore volume in the range from 0.1 to 1.0 cm³/g.

41. An electrode in accordance with claim 29 in which the carbon is present in the form of non-graphitic carbon comprising a plurality of randomly orientated graphene stacks having stack heights in the range from 2 to 30 nm and lateral extension values L_A in the range from 2 to 8 nm, the graphene stacks either contacting one another or being separated by amorphous carbon usually distributed throughout the structure and present between the graphene stacks in a total amount relative to the graphene stacks material of less than 10% by weight.

42. An electrode in accordance with claim 40 in which the second pores are defined between neighbouring graphene stacks and the first pores are defined by voids in the graphene stacks.

43. An electrode in accordance with claim 41 in which the second pores are defined between neighbouring graphene stacks and the first pores are defined by voids in the graphene stacks.

44. An electrode in accordance with claim 29 wherein the carbon material is present in the form of a carbon monolith.

45. A method of manufacturing an electrode in accordance with claim 29, wherein the carbon material having a hierarchical porosity is made by carbonizing a carbon monolith precursor having a porosity generating fugitive phase dispersed therein, said fugitive phase comprising particles in at least first and second size ranges, said first size range being from 10 μ

m to 100 nm and said second size range being from less than 100 nm to 3 nm, subsequently removing said fugitive phase to form a porous carbon monolith having hierarchical porosity with pores in said size ranges and subsequently depositing a conductive polymer on said carbon material having a hierarchical porosity.

46. A method in accordance with claim 45, wherein said fugitive phase is SiO₂ and is removed from said heat treated carbon monolith precursor by chemical dissolution.

47. A method in accordance with claim 45, wherein said fugitive phase is polystyrene and is removed during carbonizing of the carbon monolith precursor by vaporisation.

48. A method of manufacturing an electrode in accordance with claim 29, wherein the carbon material having a hierarchical porosity is made by:

manufacturing a mixture containing at least one carbon precursor and an organic polymer in an organic solvent,

by vaporizing the solvent until a viscous or highly viscous composition of a corresponding shaped body is obtained,

by shaping the viscous composition into a shaped body, by heating the composition of the shaped body to a temperature between 600°

C. and 1000°

C. to form a porous carbon monolith having hierarchical porosity with pores in said size ranges and wherein a conductive polymer is subsequently deposited on said carbon material having a hierarchical porosity.

49. A method in accordance with claim 48, wherein said organic polymer is polystyrene.

50. A method in accordance with claim 45, wherein said carbon precursor is mesophase pitch.

51. A method in accordance with claim 45, wherein said carbon precursor is a naphthol solution.

52. A method in accordance with claim 45, wherein said electrically conductive polymer is potentiostatically electrodeposited on said carbon material and is preferably polyaniline.

53. A method in accordance with claim 52 wherein said electrically conductive polymer is electrodeposited on said carbon material having hierarchical porosity in an electrochemical cell having the carbon material as anode and an electrolyte comprising aniline in sulfuric acid, preferably 0.05M aniline in 1M H₂SO₄.

54. A method in accordance with claim 45, wherein said electrically conductive polymer is one of polypyrrole and polythiopene or a mixture of the foregoing, or a mixture of one or both of them with polyaniline

55. A supercapacitor incorporating an electrode comprising a conductive carbon material of hierarchical porosity coated with an electrically conductive polymer, wherein the porous electrically conductive carbon material includes graphene stacks and has first and second pores in first and second different pore size ranges respectively, wherein said first pores are of irregular shape in three dimensions, are interconnected to form transport passages through said carbon material and have sizes in the size range from 10 μ

m to 100 nm, wherein said second pores are defined between neighbouring graphene stacks, are of irregular shape in three dimensions, are interconnected, communicate directly or indirectly via other second pores with said first pores and have sizes in the size range from less than 100 nm to 3 nm and wherein said graphene stacks defining said second pores form wall material between said first pores.

56. A supercapacitor incorporating an electrode of carbon material having a hierarchical porosity and made by carbonizing a carbon monolith precursor having a porosity generating fugitive phase dispersed therein, said fugitive phase comprising particles in at least first and second size ranges, said first size range being from 10 μ

m to 100 nm and said second size range being from less than 100 nm to 3 nm, subsequently removing said fugitive phase to form a porous carbon monolith having hierarchical porosity with pores in said size ranges and subsequently depositing a conductive polymer on said carbon material having a hierarchical porosity.

57. A supercapacitor incorporating an electrode of carbon material having a hierarchical porosity and made by:

manufacturing a mixture containing at least one carbon precursor and an organic polymer in an organic solvent,

by vaporizing the solvent until a viscous or highly viscous composition of a corresponding shaped body is obtained,

by shaping the viscous composition into a shaped body, by heating the composition of the shaped body to a temperature between 600°

C. and 1000°

C. to form a porous carbon monolith having hierarchical porosity with pores in said size ranges and wherein a conductive polymer is subsequently deposited on said carbon material having a hierarchical porosity.